Many applications depend on sending and receiving relatively large amounts of data. Technologies based on transmitting data using light are a convenient option that offers high network bandwidth. (Transmitting data using light is hereinafter referred to as optical communication.) There are a number of devices that use light for transmitting information. For example, optical fibers are capable of transmitting data over vast distances providing high network bandwidth. Photonic integrated circuits (PIC) are another example, in which multiple photonic functions are integrated for providing functionality for light signals.
Some systems for optical communication are based on emission and detection of modulated laser light acting as data carrier. In particular, semiconductor devices for laser emission and detection are now commonplace in optical communication systems. For example, vertical-cavity surface emitting lasers (VCSELs) may be used for laser emission. Laser detector semiconductor photodiodes may be used for laser detection. An optical waveguide (e.g., an optical fiber) may be used for transmitting the laser light between laser emitters and detectors.